1. Field of the Invention
The present invention relates to a judgment mechanism of power supply devices, and more particularly, to a power supply device, a portable electronic apparatus and a related method for determining types of a power supply device.
2. Description of the Prior Art
In today's market, mobile phones have their own mobile chargers in accordance with their brands or models. For example, a mobile charger labeled as “H Brand” can provide the use for a mobile phone labeled as the “H Brand” only, and is unable to perform charging upon mobile phones labeled as “N Brand” or “M Brand”. However, China's Ministry of Information Industry (CMII) promotes that the connector interface of the mobile chargers must conform to universal serial bus (USB) specification; that is to say, the same mobile charger can be used to perform charging upon the mobile phones with different brands or different models.
Generally speaking, USB transmission interface has five transmission terminals that respectively are: a VBUS terminal, a D+ terminal, a D− terminal, an ID terminal, and a GND terminal. As far as a charger conforming to China Charger's specifications is concerned, the D+ terminal and the D− terminal are short circuited inside the body of the charger, and therefore this feature can be used as a recognition feature of the China Charger's specifications.
When the USB connector of the mobile phone is connected to a USB connector of an electronic device, the mobile phone must have the ability to accurately determine the type of the electronic device, such that the mobile phone can operate correctly. As an illustration, when the electronic device is a charger, the mobile phone can charge itself by making use of this charger. As another illustration, when the electronic device is not a charger and is a computer host, the mobile phone is able to transmit data between the computer host. Moreover, even though the abovementioned concept of adopting the same mobile charger to perform charging upon the mobile phones with different brands or different models is convenient, there are too many types of mobile chargers existent in today's market and it is impossible to control their qualities. If a mobile phone that allows chargers with any brand to perform charging upon it without any restrictions, the mobile phone may be continuously charged, which leads to voltage levels of its internal capacitors exceed the nominal values so as to burn out the capacitors. What is more, it may cause damage to other components or can not meet safety standards, which is dangerous. Hence, a portable electronic apparatus capable of determining the type of the connected electronic device and a related judgment mechanism are required.